Im still voting for Sadie-Jennifer! Sadie as a diminutive of Sarah, which is Hebrew from princess - not a bad meaning at all!

If they liked Willow, they might like Marlowe? Marlowe-Jenna maybe? Not the best meaning (driftwood), but the flow of the name is great.

If they liked Laura, then what about Laurel? Jenna-Laurel is pretty, and the meaning of Laurel is "Laurel tree". The laurel is also a key component in Greek Mythology, where a laurel wreath is used as a marker of victory. (Jenna-Lorelei could also be an option, but if meaning is super important to them, it is less than ideal)